Reminder: Definition of Computation

1
Reminder Definition of Computation

• Symbol system
• Symbol shapes arbitrary
• Symbol manipulations (algorithms) all syntactic
  (based on shape, not meaning)
• Implementation-independent
• Semantically interpretable (meaningful)

2
Strong AI (Computationalism or Cognitivism

• Mind is a computer program (I.e., cognition is
  computation)
• Brain is Irrelevant (I.e., computation is
  implementation-independent)
• Turing Test is Decisive (I.e., the T2-passing
  symbol system has a mind)

3
Chinese Room Argument

• Suppose SS is the T2-passing symbol system
  (passes in Chinese, so has a mind, understands
  Chinese)
• Because computation is implementation-independent,
  every implementation of SS understands Chinese
• Searle implements SS -- but fails to understand
  Chinese

4
What went wrong?

• System Reply Searle doesnt understand, the
  system does (but Searle is the system!)
• Turing Test is at fault (T2 perhaps, but T3?)
• Symbol Grounding Problem (symbols and T2 are not
  enough symbol meanings must be grounded via T3

5
The Symbol Grounding Problem

• Chinese/Chinese Dictionary-Go-Round
• Grounding symbols in T3 (robotic) capacity
• Neural nets and other nonsymbolic (analog,
  dynamic) functions
• Hybrid symbolic/nonsymbolic systems
• Categorical Perception (sensorimotor toil
• Dictionary Grounding (symbolic theft)

6
Dennett on Robotics and Reverse-Engineering

• Dennett is a behaviourist/instrumentalist
• For him, mental capacities are just behavioural
  capacities
• Hence TT capacity mind
• Reverse-engineering the mind is
  reverse-engineering its behavioural capacities
• Robotics is the way to design and test theories
  of mind

7
Critiques of connectionism

• Cognition may not be just computation, but is it
  just connectionism either?
• Pinker/Princes critique of Perceptron past-tense
  learning
• Pylyshyn/Fodors critique of systematicity

8
Chalmers on Computation

• What is computation for Chalmers?
• Reconfiguring hardware via software
• What can be reconfigured into what, via software?
• Can a computer be reconfigured into a plane?
• Why should thinking (cognition) differ from
  flying?